Prefabricated self-forming arch lining structure for tunnels and its construction method

Abstract

This invention relates to a prefabricated self-forming arch secondary lining structure for tunnels and its construction method. Existing secondary lining structure construction suffers from problems such as high labor intensity, long construction period, and low level of mechanization. The secondary lining structure of this invention includes an invert arch, precast concrete blocks, and hollow steel structural blocks, all equipped with circumferential tensioning ducts. Tensioning ropes are inserted into the tensioning ducts, and under the traction of the tensioning ropes, the invert arch, precast concrete blocks, and hollow steel structural blocks circumferentially form the secondary lining structure. The hollow steel structural blocks are located at the top, the precast concrete blocks on both sides, and the invert arch at the bottom. This invention adopts a prefabricated construction method, allowing for factory-made precast concrete blocks and hollow steel structural blocks, resulting in more controllable quality and a high level of mechanization. During assembly, tensioning is performed after tensioning ropes are inserted into the precast concrete blocks and hollow steel structural blocks, causing the various components to form a circumferential arch under tension, significantly improving construction speed.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering construction technology, specifically to a prefabricated self-forming arch secondary lining structure for tunnels and its construction method. Background Technology

[0002] When designing and constructing a highway tunnel structure system according to the principles of the New Austrian Tunneling Method (NATM), the structure system mainly includes initial support and secondary lining. The initial support consists of anchor bolts, shotcrete, steel arches, etc., while the secondary lining uses cast-in-place concrete or reinforced concrete. Geotextile and waterproof membrane are laid between the initial support and the secondary lining.

[0003] Based on tunnel construction practice, the secondary lining of highway tunnels using cast-in-place concrete or reinforced concrete construction involves numerous processes such as formwork erection, concrete pouring, formwork removal, and curing. This process results in high labor intensity for workers, a long curing period for the secondary lining, and low levels of mechanization. Furthermore, considering the mechanical characteristics of highway tunnel excavation, early construction of the support structure and tunnel support system, and early closure into a ring, can significantly and effectively control tunnel crown settlement and perimeter convergence. Therefore, it is necessary to propose secondary lining construction techniques for the New Austrian Tunneling Method (NATM) that can effectively reduce the labor intensity of construction workers, shorten the construction period, and achieve a high level of mechanization, thereby accelerating construction speed and improving the ability to control tunnel deformation. Summary of the Invention

[0004] The purpose of this invention is to provide a prefabricated self-forming arch secondary lining structure for tunnels and its construction method, so as to at least solve the problems of high labor intensity, long construction period and low level of mechanization in the construction of existing secondary lining structures.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A prefabricated self-forming arch secondary lining structure for tunnels, the secondary lining structure including an invert arch, precast concrete blocks and hollow steel structure blocks, wherein circumferential tensioning ducts are provided in the invert arch, the precast concrete blocks and the hollow steel structure blocks.

[0007] Tensioning ropes are inserted into the tensioning ducts of the inverted arch, the precast concrete block, and the hollow steel structure block. Under the traction of the tensioning ropes, the inverted arch, the precast concrete block, and the hollow steel structure block form the secondary lining structure in a circumferential direction. In the secondary lining structure, the hollow steel structure block is located at the top, the precast concrete block is located on both sides, and the inverted arch is located at the bottom.

[0008] Furthermore, the inverted arch has a space in the middle for accommodating the prestressing tensioning device.

[0009] Furthermore, the precast concrete block includes a first precast concrete block and a second precast concrete block;

[0010] The first precast concrete block is located at the bottom of both sides and is connected to the inverted arch. There is one first precast concrete block on each side. The top of the first precast concrete block has an insertion groove or an insertion tenon.

[0011] The second precast concrete block is located on both sides and between the hollow steel structure block and the first precast concrete block. At least two second precast concrete blocks are provided on each side. The top and bottom of the second precast concrete block are provided with insertion grooves or insertion protrusions.

[0012] The first precast concrete block and the adjacent second precast concrete block, as well as the adjacent second precast concrete blocks, are connected to each other through corresponding insertion grooves and insertion protrusions.

[0013] Furthermore, the hollow steel structure block includes two hollow steel boxes, one end of which is provided with a shaft hole;

[0014] One of the hollow steel boxes has a shaft hole at one end with a smaller outer perimeter than the other hollow steel box. The two hollow steel boxes have shaft holes at one end that are inserted into each other. After the shaft holes are aligned, a rotating shaft is inserted.

[0015] Furthermore, the other end of the shaft hole in the hollow steel box is provided with a insertion groove or a insertion tenon;

[0016] The hollow steel box and the adjacent second precast concrete block are connected to each other by corresponding insertion grooves and insertion tenons.

[0017] Furthermore, the hollow steel box is provided with a circumferential tensioning channel, which is located beside the shaft hole.

[0018] Furthermore, the inverted arch is a cast-in-place structure.

[0019] Furthermore, the bottom profile of the invert arch is consistent with the inner profile of the initial support, and the top surface of the invert arch is a plane.

[0020] The end of the first precast concrete block that connects to the inverted arch is a flat surface.

[0021] On the other hand, a construction method for a prefabricated self-forming arch secondary lining structure for tunnels is provided, the method comprising:

[0022] Excavate the tunnel and implement initial support;

[0023] Cast the invert arch and reserve tensioning ducts and spacing spaces;

[0024] The precast concrete blocks and hollow steel structure blocks are transported to the construction site by a mobile trolley. The precast concrete blocks and hollow steel structure blocks are placed in sequence on the mobile trolley and tensioning ropes are threaded through them.

[0025] Prestressed tensioning devices are placed in the gaps, and tensioning ropes are further inserted from the outside of the invert arch and exited from the inside. Then, the prestressed tensioning devices are used for tensioning. Under the traction of the tensioning ropes, the invert arch, precast concrete blocks, and hollow steel structure blocks form a secondary lining structure in a circumferential direction.

[0026] Remove the prestressing tensioning device and repeat the construction process;

[0027] Construct a central drainage ditch in the tunnel at the interval where the prestressed tensioning device is located.

[0028] Furthermore, after the inverted arch, precast concrete blocks, and hollow steel structure blocks are circumferentially assembled into the secondary lining structure, wall thickness grouting is performed through pre-reserved holes.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] This invention employs a prefabricated construction method, allowing for the factory production of precast concrete blocks and hollow steel structure components. This ensures better quality control, facilitates construction and installation, and promotes a high level of mechanization. Furthermore, the construction process is simple and the construction speed is fast. In addition, the precast concrete blocks do not interfere with the layout of the tunnel's electromechanical facilities, thus better meeting the needs of the tunnel's later operational phase.

[0031] This invention assembles a secondary lining structure using precast concrete blocks and hollow steel structural components. During assembly, tensioning ropes are inserted into the precast concrete blocks and hollow steel structural components, causing various components to form a circumferential arch under tension, significantly improving construction speed. The hollow steel structural components are positioned at the top center of the secondary lining structure after tensioning. A rotation axis is designed into the structure, allowing the relative angles of each part of the hollow steel structural component to change in real time under the action of the rotation axis, adapting to the actual shape of the tunnel profile and improving the ability to control tunnel construction deformation. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the initial construction phase in an embodiment of the present invention.

[0034] Figure 2 This is a structural diagram of the first precast concrete block in an embodiment of the present invention.

[0035] Figure 3 This is a structural diagram of the second precast concrete block in an embodiment of the present invention.

[0036] Figure 4 This is a diagram of the hollow steel structure block before tensioning in an embodiment of the present invention.

[0037] Figure 5 This is a diagram showing the tensioned state of the hollow steel structure block in an embodiment of the present invention.

[0038] Figure 6 This is a schematic diagram of the prefabricated self-forming arch secondary lining structure of the tunnel in an embodiment of the present invention.

[0039] Figure 7 This is a schematic diagram of the arrangement of reserved holes in the precast concrete blocks in an embodiment of the present invention.

[0040] The diagram is labeled as follows:

[0041] 1-Initial support, 2-First precast concrete block, 3-Second precast concrete block, 4-Hollow steel structure block, 5-Movable trolley, 6-Inverted arch, 7-Prestressed tensioning device, 8-Tensioning duct, 9-Interlocking groove, 10-Interlocking tenon, 11-Hollow steel box, 12-Rotating shaft, 13-Shaft hole, 14-Tensioning rope, 15-Base, 16-Load-bearing structural steel beam, 17-Segment suction cup, 18-Reserved hole. Detailed Implementation

[0042] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0043] In the description of this patent, it should be understood that the terms "middle," "upper," "lower," "longitudinal," "lateral," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this patent and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent. Similarly, the terms "first," "second," etc., are used solely to more clearly describe structural features for the purpose of distinguishing structures and should not be construed as limitations on relationships, order, importance, etc.

[0044] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0045] In the description of the specific implementation, the tunnel length direction is defined as longitudinal, and the direction perpendicular to the tunnel length direction is defined as transverse.

[0046] Example 1: Prefabricated self-forming arch lining structure for tunnels

[0047] When constructing highway tunnels according to the New Austrian Tunneling Method (NATM), the secondary lining structure is mostly cast-in-place. Currently, with the introduction of prefabricated construction technology, there are also construction practices that involve prefabricating and assembling the secondary lining structure in sections. The tunnel prefabricated self-forming arch secondary lining structure of this invention combines cast-in-place technology and prefabrication technology, constructing a semi-prefabricated, semi-cast-in-place self-forming arch secondary lining structure through a novel construction scheme.

[0048] like Figure 1 and Figure 6 The secondary lining structure in this embodiment includes an inverted arch 6, precast concrete blocks, and hollow steel structural blocks 4. The inverted arch 6 is a cast-in-place structure, while the precast concrete blocks and hollow steel structural blocks 4 are factory-prefabricated structures. Each of the inverted arch 6, precast concrete blocks, and hollow steel structural blocks 4 has a circumferential tensioning channel 8. Tensioning ropes 14 are inserted into these tensioning channels 8, and the tensioning ropes 14 are tensioned by a prestressing tensioning device 7. Under the traction of the tensioning ropes 14, the inverted arch 6, precast concrete blocks, and hollow steel structural blocks 4 circumferentially form the secondary lining structure, as shown below. Figure 6 The secondary lining structure is constructed longitudinally, ring by ring, along the tunnel length. In the tensioned secondary lining structure, hollow steel structural blocks 4 are located at the top, precast concrete blocks on both sides, and the invert arch 6 at the bottom. The invert arch 6 has a central space for accommodating the prestressed tensioning device 7, effectively creating a space in the tunnel center where the invert arch 6 is symmetrically cast. Later, a central tunnel drainage ditch can be constructed within this space as required. The bottom profile of the invert arch 6 matches the inner profile of the initial support 1, while the top surface is flat.

[0049] The precast concrete blocks in this embodiment include a first precast concrete block 2 and a second precast concrete block 3. The two types of precast concrete blocks have structural differences based on their different arrangement positions. For example... Figure 1 and Figure 2The first precast concrete block 2 is located at the bottom of both sides and connects to the invert arch 6. One first precast concrete block 2 is provided on each side. The top of the first precast concrete block 2 has an insertion groove 9 or an insertion tenon 10, and the bottom is flat. After tensioning, it connects to the top surface of the invert arch 6. For example... Figure 1 and Figure 3 The second precast concrete blocks 3 are located on both sides and between the hollow steel structure block 4 and the first precast concrete block 2. At least two second precast concrete blocks 3 are provided on each side; in this embodiment, a total of eight are provided. The number and shape of the second precast concrete blocks 3 can be adjusted according to the actual tunnel cross-section size. The top and bottom of the second precast concrete blocks 3 are provided with insertion grooves 9 or insertion tenons 10. The first precast concrete block 2 and adjacent second precast concrete blocks 3, as well as adjacent second precast concrete blocks 3, are interlocked through corresponding insertion grooves 9 and insertion tenons 10, providing a limiting function while enhancing overall stability.

[0050] like Figure 4 and Figure 5 The hollow steel structure block 4 includes two hollow steel boxes 11. One end of each hollow steel box 11 has a shaft hole 13, the direction of which is aligned with the tunnel length. The outer perimeter of the end of one hollow steel box 11 with the shaft hole 13 is smaller than that of the other hollow steel box 11. The ends of the two hollow steel boxes 11 with the shaft holes 13 are interlocked, and a rotating shaft 12 is inserted after the shaft holes 13 align. The rotating shaft 12 is longitudinally positioned. Under the action of the rotating shaft 12, the two hollow steel boxes 11 can rotate around the rotating shaft 12 in a plane perpendicular to the tunnel length, changing the included angle between them and allowing for some flexibility to accommodate the overall structure after tensioning. The other end of the hollow steel box 11 with the shaft hole 13 has an insertion groove 9 or an insertion tenon 10. The hollow steel box 11 and the adjacent second precast concrete block 3 are also interlocked through corresponding insertion grooves 9 and insertion tenons 10, ensuring overall stability and mutual positioning. The circumferential tensioning channel 8 set inside the hollow steel structure block 4, i.e. the circumferential tensioning channel 8 set inside the hollow steel box 11, is located beside the shaft hole 13 inside the hollow steel box 11 in order not to conflict with the position of the shaft hole 13 and the rotating shaft 12.

[0051] Example 2: Construction method of prefabricated self-forming arch secondary lining structure for tunnels

[0052] like Figure 1 and Figure 6 The method of this embodiment is used to construct the structure described in Embodiment 1, and the method includes:

[0053] Step 1: Excavate the tunnel and construct initial support according to the design drawings.

[0054] Step 2: Excavate and pour the invert arch 6 and reserve tensioning ducts 8 and spacers.

[0055] Step 3: Transport the precast concrete blocks and hollow steel structure blocks 3 to the construction position using the movable trolley 5. The precast concrete blocks and hollow steel structure blocks 3 are placed in sequence on the movable trolley 5 and tension ropes 14 are threaded through them to ensure that after tensioning, the hollow steel structure blocks 3 are located at the top and the precast concrete blocks are located on both sides. This step requires two movable trolleys 5 to move on the surface of the inverted arch 6 on the left and right sides. The precast concrete blocks and hollow steel structure blocks 3 on both sides are connected in series by a tension rope 14.

[0056] This step requires a movable trolley 5, such as Figure 1 The movable trolley 5 consists of a base 15, a load-bearing steel beam 16, and a segment suction cup 17, enabling the positioning and assembly of segments. Here, "segment" refers to precast concrete blocks and hollow steel structure blocks 3.

[0057] Step 4: Place the prestressed tensioning device 7 in the gap, and further insert the tensioning rope 14 from the outside of the invert arch 6 and out from the inside. Then tension it through the prestressed tensioning device 7. Under the traction of the tensioning rope 14, the invert arch 6, the precast concrete block and the hollow steel structure block 4 form a secondary lining structure in a circumferential direction.

[0058] Step 5: Grout the wall thickness through the reserved hole 18. The reserved hole 18 serves as a grouting hole and can be placed on the open inner side of the precast concrete block to facilitate the grouting operation.

[0059] Step 6: Remove the prestressed tensioning device 7, repeat the construction process, and construct the tunnel center drainage ditch at the original position of the prestressed tensioning device 7.

[0060] Following the steps described above, the secondary lining structure is constructed longitudinally, ring by ring, along the tunnel length.

[0061] This invention employs a prefabricated construction method, allowing for factory-made precast concrete blocks and hollow steel structure components, resulting in more controllable quality, convenient construction and installation, and a high level of mechanization. During assembly, tensioning is achieved by inserting tension ropes into the precast concrete blocks and hollow steel structure components, causing the various components to form an arch around themselves under tension, significantly increasing construction speed. Furthermore, the hollow steel structure components, after tensioning, are positioned at the center of the top of the secondary lining structure. The structure incorporates a rotation axis, allowing the relative angles of the different parts of the hollow steel structure components to change in real time under the action of the rotation axis, adapting to the actual shape of the tunnel profile and improving the ability to control tunnel deformation during construction.

[0062] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A prefabricated self-forming arch lining structure for tunnels, characterized in that: The secondary lining structure includes an inverted arch (6), precast concrete blocks, and hollow steel structure blocks (4). The inverted arch (6), the precast concrete blocks, and the hollow steel structure blocks (4) are all provided with circumferential tensioning ducts (8). Tensioning ropes (14) are inserted into the tensioning ducts (8) of the inverted arch (6), the precast concrete block and the hollow steel structure block (4). Under the traction of the tensioning ropes (14), the inverted arch (6), the precast concrete block and the hollow steel structure block (4) form the secondary lining structure in a circumferential direction. In the secondary lining structure, the hollow steel structure block (4) is located at the top, the precast concrete block is located on both sides, and the inverted arch (6) is located at the bottom. The hollow steel structure block (4) includes two hollow steel boxes (11), one end of which is provided with a shaft hole (13); the outer periphery of the end of one hollow steel box (11) with the shaft hole (13) is smaller than that of the other hollow steel box (11) with the shaft hole (13), the ends of the two hollow steel boxes (11) with the shaft holes (13) are inserted into each other, and the rotating shaft (12) is inserted after the shaft holes (13) are aligned.

2. The prefabricated self-forming arch secondary lining structure for tunnels according to claim 1, characterized in that: The inverted arch (6) has a space in the middle for accommodating the prestressed tensioning device (7).

3. The prefabricated self-forming arch secondary lining structure for tunnels according to claim 1, characterized in that: The precast concrete block includes a first precast concrete block (2) and a second precast concrete block (3); The first precast concrete block (2) is located at the bottom of both sides and is connected to the inverted arch (6). There is one first precast concrete block (2) on each side. The top of the first precast concrete block (2) has an insertion groove (9) or an insertion tenon (10). The second precast concrete block (3) is located on both sides and between the hollow steel structure block (4) and the first precast concrete block (2). At least two second precast concrete blocks (3) are provided on each side. The top and bottom of the second precast concrete block (3) are provided with insertion grooves (9) or insertion protrusions (10). The first precast concrete block (2) and the adjacent second precast concrete block (3) are connected to each other by corresponding insertion grooves (9) and insertion protrusions (10).

4. The prefabricated self-forming arch secondary lining structure for tunnels according to claim 3, characterized in that: The hollow steel box (11) is provided with a shaft hole (13) at one end and a insertion groove (9) or insertion tenon (10) at the other end. The hollow steel box (11) and the adjacent second precast concrete block (3) are connected to each other by corresponding insertion grooves (9) and insertion tenons (10).

5. The prefabricated self-forming arch lining structure for tunnels according to claim 1, characterized in that: The hollow steel box (11) is provided with a circumferential tensioning channel (8), which is located on the side of the shaft hole (13).

6. The prefabricated self-forming arch secondary lining structure for tunnels according to claim 3, characterized in that: The inverted arch (6) is a cast-in-place structure.

7. The prefabricated self-forming arch secondary lining structure for tunnels according to claim 6, characterized in that: The bottom profile of the inverted arch (6) is consistent with the inner profile of the initial support (1), and the top surface of the inverted arch (6) is a plane. The end of the first precast concrete block (2) that connects to the inverted arch (6) is a plane.

8. A construction method for a prefabricated self-forming arch secondary lining structure for tunnels, characterized in that: The method includes: Excavate the tunnel and implement initial support (1); Cast the invert arch (6) and reserve tensioning ducts (8) and spacing gaps; The precast concrete blocks and hollow steel structure blocks (4) are transported to the construction site by a mobile trolley (5). The precast concrete blocks and hollow steel structure blocks (4) are placed in sequence on the mobile trolley (5) and tension ropes (14) are threaded through them. A prestressed tensioning device (7) is placed in the space between the gaps. The tensioning rope (14) is further inserted from the outside of the invert arch (6) and out from the inside. Then, the prestressed tensioning device (7) is used for tensioning. Under the traction of the tensioning rope (14), the invert arch (6), the precast concrete block and the hollow steel structure block (4) form a circumferential lining structure. Remove the prestressing tensioning device (7) and repeat the construction process; Construct a central drainage ditch in the tunnel at the interval where the prestressed tensioning device (7) is located.

9. The construction method of the prefabricated self-forming arch secondary lining structure for tunnels according to claim 8, characterized in that: After the inverted arch (6), precast concrete blocks and hollow steel structure blocks (4) are circumferentially assembled into the secondary lining structure, wall thickness grouting is performed through the reserved holes (18).

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